1. Field of Invention
The present invention relates to performance enhancing footwear. More specifically the present invention relates to footwear incorporating at least one piezoelectric spring which, when activated, enables the wearer of the footwear to jump higher or run faster.
2. Description of the Prior Art
The present invention is a unique article of footwear which incorporates a piezoelectric spring system which may be advantageously used in a preferred embodiment of the invention to enable the wearer of said article of footwear to run faster or jump higher than without said article of footwear. Energy generated by a piezoelectric element as a result of the impact of the footwear against the ground is stored in an energy storage circuit and is later released at an advantageous time.
The prior art includes devices which emit light when the footwear impacts or departs from the ground. Lighted footwear seen in the prior art typically comprises one or more sources of electric light, a small portable power source, such as a dry-cell battery, and electrical circuitry to connect the power source to the light sources electrically, which circuitry usually includes sensing means for sensing the desirable dynamic forces and switching the light sources on and off in a desirable fashion.
In U.S. Pat. No. 45,188,447, L. Chiang, et al., describe a lighted footwear system in which the lights are actuated by the impact of the footwear against an object, such as the ground. In this prior system, a piezoelectric crystal operates as a voltage generator to generate a brief voltage pulse, the amplitude of which is related to the amount of inertial force incident upon the crystal. The voltage pulse is used as the input of the battery-driven amplifier, which, in turn, drives the lights, such that the intensity of the single pulse of light emitted by the lights is related to the amount of force with which the footwear impacts the object. The Chiang, et al. device and other prior lighted footwear devices create a lighted effect that is novel and pleasing to the eye, but does not enhance the wearer's performance characteristics (i.e., running or jumping) in any way.
Accordingly, an inertially responsive article of footwear which is actuated by impact of the footwear against the ground and which improves the wearer's running and jumping capabilities and which incorporates a piezoelectric element capable of sustaining high loads is highly desirable.